Ok, I've got a 98 Dakota 2.5. I've had starting problems and running problems, especially when it gets down to 50 or below. I read about another guy on a different site that had the same truck, with the same issues, except his would not start at all. I didn't see a reply from him on whether he got it fixed or not.

However. It was suggested to him that there was a wire splice corrosion problem that effected 95 year models. I saw a another guy who had this problem, and he showed pictures of how he fixed it, but I can't tell what year model he has, nor did he say.

Is this an issue on 98's?

 

Never had a problem with my 98 2.5 like that, 50 you sure on that that’s not very cold when it gets down to the 20 range she is a little hard but not bad.

Not sure what you are after

Tune it up first then see what happens check the plugs wires everything check for vacum leaks

If still running bad I would go for your sensors first is the MAP then TPS then the coolant temp sensor then Air Temperature Sensor then the O2 sensors

 

With the Air Temperature Sensor try just pulling it out and cleaning it off with some carb or break spray cleaner they tend to get a coat of oil on them. Clean your throttle body you may as well get it done very easy to do this will also get you a good look at your vacuum lines under the throttle body attached to the manifold check for cracked vacuum lines in that area as that is the place they will rot easy. Be careful cleaning the throttle body there are some things you need to have care with and some things not to clean like the IAC only clean by hand never spray it with cleaner directly.

An ok vid on cleaning the 2.5 this guy is a spazz at it but worth watching to learn something this is off a Jeep but its the same engine and parts

 

Good vid on replacing the MAP this off a different engine but the same throttle body so this is how to do it

The easy way to do it is remove the throttle body 100 times easier to do it that way you can see what you are after and be very careful with that little elbow DONT LOSE IT or you are in trouble

 

ah yes as far as I know and have heard if you look at the entire wireing harness on your truck you'll see that it is tapped up with (my best guess) cloth hockey tape it gets wet and traps water in it causing corrosion especially at all the splices. This has been an issue for a long time. had issues on my 92 3.9l my friend had issues on his 96 v8 so good luck tracking it down.

 

Why do you think its a bad splice?

I suspect the things I listed I would try them first the MAP and air temp could be a problem along with the coolant temp they dictate how the engine will run in different temp conditions.

The starting problem could be a few different things


Making sure everything is up to snuff like a tune up is a good start get the battery checked out also

 

I've replaced:
battery
distributor
cap & rotor
map
tps
intake air temp sensor
cleaned the t-body and IAC
Fixed an exhaust leak

The problem is consistency. Like this morning, 39 degrees and it started on the first try. Went to the store, shut it off, got back in, and it started right up. But, if it is damp or humidity is high, then it will take several tries. I also have no codes since clearing them after installing the distributor.

 

What about the sparkplug wires and the sparkplugs?

Check them or replace them you need to know if they are in good condition.

Stating up is your main problem correct is your starter original and how is the starter power cable?

Is it clean or corroded replace the starter cable and see what happens

Do you have any other problems does it run good?

Do you see any lights dim rather low as you try to start it?

 

Can you give us a more detailed description of what is happening please?

Does it just not crank over or it’s just weak as it cranks?

Does the starter solenoid click or not click?

 

Check the fuel pressure. Could be signs of a failing fuel pump